Self Regulating Heat Cable
Heat Trace Cable, sometimes called heating cable, is used for multiple applications. Freeze Protection or Process Temperature Maintenance self heating-regulating cables are designed to provide freeze protection or process temperature maintenance to metallic and nonmetallic piping, tanks and equipment.
Whenever the heat loss of the insulated pipe, tanks or equipment increase(as ambient temperature drops), the heat output of the cable increases. Conversely, when the heat loss decreases(as the ambient temperature rises or product flows), the cable reacts by reducing its heat output. This type of heating cable are approved for use in ordinary areas and hazardous areas.
Working-principle
The heat output of self-regulating cable varies in response to the surrounding conditions along the entire length of a circuit. When the cable temperature reaches the set point the resistance goes high and then no more heat is supplied. This means heat is only supplied where needed along the length of the cable. These cables use two parallel bus wires which carry electricity but don`t create significant heat. They are encased in a semi-conductive polymer. This polymer is loaded with cartoon as the polymer element heats, it allows less current to flow.
The benefits of this cable are the ability to cut the length in the field, it is more rugged but not necessarily more reliable than series or zone heaters, it cannot over-heat itself so in theory it can be crossed, but it is bad practice to install tape in this way.